An embodiment of the microneedle array is known from WO 02/064193. The known microneedle array comprises a set of microneedles of a suitable geometry projecting as an out of plane structure from a base support. The known microneedle array may be produced using conventional methods used to make integrated circuits, electronic packages and other microelectronic devices, which may be augmented by additional methods used in the field of micromachining and micromolding. The known three-dimensional arrays of microneedles can be fabricated using combinations of dry-etching processes; micromold creation in lithographically-defined polymers and selective sidewall electroplating, or direct micromolding techniques using epoxy mold transfers. The known microneedle array is formed from a suitable polymer material and can be produced using (i) etching the polymer microneedle directly, (ii) etching a mold and then filling the mold to form the polymer microneedle product, or (iii) etching a microneedle master, using the master to make a mold and then filling the mold to form the polymer microneedle replica of the master.
Over the recent years more and more microneedles have become popular to penetrate the skin barrier and thus introduce means for creating a microfluidic pathway across the skin either for drug delivery, or for analytics of extracted fluids. Microneedles as known in the art may be used in skin patches, in particular in skin patches for delivering a drug across a barrier, for example, skin. So-called intelligent patches, comprising means for delivery of a drug having relatively big molecules, are described in J.-H. Park et al “Polymer particle-based micromolding to fabricate novel microstructures”, Biomed Microdevices (2007) 9: 223-234. However, commercialization of such intelligent skin patches having porosity as an actual functional feature has been difficult due to lack of inexpensive production method as well as due to lack of suitable production materials for patch production with required properties.
The known microneedle production method according to WO 02/064193 has a disadvantage that the method of producing microneedle arrays is relatively expensive. The method of microneedle production according to J.-H. Park et al has a disadvantage that the resulting porous microneedles are relatively fragile.